Meter



y June 23, 1925. 1,542,883

F. HOLDEN METER FiledfFeb. 27, 1922 3 Sheets-Sheet 1 Figi.

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F. HOLDEN METER Filed web. 2v, 1922 s sheets-sheet a W Z d l'l/vesLn/tanlHO Le/6.274

Patented June 23, 1925.

UNITED STATES 1,542,888 PATENT or-FICEl FRANK HOLDEN, OFHAMPSTEAD-LONDON, ENGLAND, ASSIGNORVOF ONE-THIRD TO MEASUREMENT,LIMITED, 0F LONDON, ENGLAND, AND ONE-THIRD -TO ,LA C011- PAGNIE POUR LAFABRICATION DES COMPTEURS ET MATRIEL DUSINES AGAZ,

' 0F PARIS, FRANCE.

' METER.

Appiication mea February 27, 192'2. vserial' No. 589,587.'A

To allrwhom t may ccmcewt:` v

Be it known that I, FRANK HOLDEN, a citizen of the United States ofAmerica,

and residing at 34, Frognal, Hampstead,

London, N. W. 3, England, have invented certain new and usefulImprovements in Meters, of which the following is a specication.

This invention relates to electric measuring instruments or meters, withparticular reference to meters of .the vmercury motor type. Y A.

Meters of this type as hitherto constructed usually comprise aibell ordisc armature of conducting material partially or wholly submerged inavbath ofvmercury and rotating in a magnetic field.- In the case of abell-shaped armature a cylindrical core of magneticv material isarranged withiny the bell Vand magnetic pole pieces secured to the endsof the limbs of a permanent magnet are mountedfin close proximity to theouterpe'riphery of the bell, the magnetic circuit beingl completedbetween the poles of the permanent magnet by means of the core locatedwithin the bell. The current to be measured is passed through themercury andbell in the'mercury cup and the interaction between thiscopper bell and the magnetic field causes the bell to rotate,

the rotation of the bell being transmitted through a train of wheels toany suitable form of indicating mechanism. Y v The object of the presentinvention is to provide an improvedI construction of electricity meterof the above type which will be simple and cheap to construct, compactin compass and easy to instal, andl which will'also be of a high orderof sensitivity and capable of giving very accurate results.

Thel invention consists in an electricity meter of the type referred toin which the polesof the magnet are located within the mercury cup.

The invention also consists in an electricity meter of the type referredto andhaving a bell-shaped armature in which the poles of the permanentlmagnet are located witnin the bell.

The invention also consists in an elec-V tricity meter ofy the abovecharacter, in which the magneticcircuit is completed by a ring ofmagnetic material forming a 'wall of the mercury cup.

The invention also consists in an electricity meterof the type referredto, comprising a bell-shaped armature, a permanentkto form the mercurycup.

The invention also' comprises other r details and arrangementshereinafter described or indicated.

The accompanying `drawings illustrate one mode of carrying out theinvention.

Figure l is a side sectional elevation showing one convenient form ofmeter constructed in accordance with the invention;

Iiigure 2 lis a front sectional elevation, an Y y f vFigures 3 Yand 4:are views illustrating a detaih w j Fig.,5 isan enlarged fragmentarysectional detail of the plate and terminal structure.

In carrying my invention into effect in one convenient manner, I provideaperma-v nent 'magnet a embedded in insulation a and made of cobaltsteel or` other suitable metal of high ret-entiveness, so that it maytherefore be made of suitably small dimensionsand consequently locatedwholly within they bell b, the external'magnetic circuit beingVcompleted by a ring c of soft iron or other good magnetic materialwhich is adaptedto surround the bell. yThe permanent magnet a is securedto a base plate d from which itis suitably insulated by insulation 4eand the said base plate d withv an upper plate f are secured .to thelower and upper edges respectively of thev ring c in such manner thatthey form ac'losed vessel which is adapted to be filled with mercury andforms the mercury cup for'thel meter.

The bell b is carried byv upper and lower jewelledor other bearings `g,L, so Vthat 'it may rotate freely by reason ofthe torqueA set up by theIinteraction of the copper bell and the magnetic field, and it will beunderstood that `the ends of the permanent magnet a are'preferablyformed concentric withthe outerfring c and that there is suiicientclearance space betweenl the poles of the magnet and the outer ring topermit of the free rotation of the bell, the various surfaces beinginsulated by vmeans of paper,

` Shellac varnishk orother suitable means,

Y spindle `z' passes therethrough, in order to prevent the escape of themercury. For this purpose the upper plate f may carry a sleeve .nsurrounding the spindle c' and forming a seating for a sealing cup owhich l is adapted normally t be held tin its open position by means ofa spring p but to be meved linto its closed .position to seal Vvthe cupby means of a pivoted lever o'r other device g actuated by a ycam rladapted to be rotated by a` suitable arm or lever s the endgt of which,for example, 'may be located, in a chambera `formed in the lowerpartei-.the lmeter and to which access may be obtained by the removal ofa cover i:

a whicjl-i,V when .the ,meter is ready Vfor insta`llation, maybe sealedin any usual or approved manner. y

The lever, or the chamber in which the same islocated, ymay begprovidedwith the wor-ds '.Open yand Closed suitably 'l0-- cated, or may have anyother convenient indication by inspection of which it may at .oncejbevascertained whether the meter is in condition for transit or forinstallationand use as a meter. a

Inthe example sho-wn the #end t off the leverfs is .providedwith thenecessary indications, as shown in Figures 3 and 4. The integratingmechanism m lmay. be carried as shownjlfrcm the upper plate f .or it maybe located fin any other convenient position. Y

In `order kto Zsimplify the `arrangements permitting of the current tobe measured being conducted to `the mercury Within the mercury cupl'provide` two copper plates or other suitable conductors fw which areclamped externally (preferably upon the under side) on the mercury cupby means of suitable clamping plates x and screws or other means",whereby apertures ,e in the mercury cup .are closed ina liquid-tightmanner while at the same `time the mercury inthe cup maires good contactwith'the conductors by reason of its having faccess thereto through theVapertures c. a The current Yto, be measured gis conducted to these.contact plates w and it will be obvious that 'thisarrangementeliminates the necessity iforthe Vusualleads .or conductors which arepassed into the mercury within the cup and for the `liquid-tightarrangements j which must he .provided in'cnjuc tion therewith.

ln the upper side of the mercury cup and opposite to or approximatelyopposite to the contacts e0 upon the Vlower side, provide 'two copperplugs y (Figure 2) amalgamate'donftheir low-.er surfaces or othersuitable conducting elements whichare yconnected'by 4a `low resistanceconductor vand in contact with the mercury withinrthecup so that bythese means the current passing through the mercury is localized and itsintensitythereby increased, with corresponding increase in the torqueexerted and consequent increased sensitivity of the ,instrument as awhole.

lt is to be noted with regard t0 the ccpper plugs y andthe conductorconnecting the same that the upper'p'late in the present case forms-theconductor; in actual prac/ tice `the'under surface of the plugs y standsslightly proud of the under surface of the plate yif and such undersurface dfthe A'plate is covered with a `layer oi insulating varnish sothatthe points of contact with the mercury in the .mercury chamber are'--le-v calized 'on the plugs 1y.' i

A meter constructed and :arranged*in-accordance with the: foregoingdescription will be "very compact in compass, simple and cheap 'to makevand eliicient ,and constant in operation.4 V

Further, by `:makinglthe cross-section of the "magnetic 'ring c .ofsuitable -area its reluctance may lbe practically Zero, and with thepermanent magnet Aarrangec'l 4diametrically lacross the .interior of thering 'the reluctance of the whole magnetic circuit can be reduced to aminimum.

Having Vnew described lmy invention what I claim Vas new and desi-re tosecure by "Letters APatent is :f 'y

l. An electricity meter of the vmercury motor type comprising incombination :a mercury chamber formed from upper and lower platesclamped to a ring of Vmagrietic material, a bell armature Awithinsaid'cham? ben, a" permanent 'magnet within said bell, and conductorsclamped upon one of said plates and adapted to 'make contact-'with themercury through aperture'sin said fpl'ate.

2. An electricity meter accordingto claim l" 1in which 'two conductorsare arranged Iin the second or' said plates opposite thecontacts, `saidyc'ondi'ict'orsfbeingconnected `by a low resistance 'conductor and beingin 'contact with the mercury vwithin the mercury chamber. V

An electricitymeter ofthe mercury motor' type comprising in combinationa mercury chamber, a bell armature within said chamber, a permanent'magnet within said bell, and conductors wholly external t0 said mercurychamber-butadapted to make contact with the mercury through apertures inthe wall o'ffsaid chamber. y I

4. An electricity meter or 'the lmercury motor type comprisingfiincembi'nation 'a mercury chamber formed of upper and lower plates securedto an intermediate ring of magnetic material, a bell armature withinsaid chamber, a permanent magnet within said bell and conductors clampedupon the outside of the lower plate and adapted to makeV contact withthe mercury through v apertures in said plate thus forming terminals bywhich the current to be measured may be led to the mercury.

5. An electricity meter of the mercury motor type comprising incombination a mercury chamber formed of upper and lower plates securedto an intermediate ring of magnetic material, a bell armature withinsaid chamber, a permanent magnet within said bell conductors clampedupon the exlgerior of the lower plate and adapted to make contact withIvthe mercury through apertures in the wall thereof and sealing means forthe mercury chamber carried upon the upper plate.

6. An electricity meter according to claim 4c in which two conductorsare arranged in the upper plate opposite the contacts of the lowerplate, said conductors being connected by a low resistance conductor andbeing in contact with the mercury within the mercury chamber.

7. An electricity meter according to claim 5 in which two conductors arearranged in the upper plate opposite the contacts of the lower plate,said conductors being connected by a low resistance conductor and beingin contact with the mercury within the mercury chamber. Y

In testimony whereof I have signed my name to this specification.

v FRANK HOLDEN.

